1996 Ford Probe Car dies when coming to stop

I recently began having having problems with my car dying when I come to a stop after driving it for 10 to 15 minutes. When I had it in for an oil change last week, the mechanic noticed it was dying and that the 'check engine' light was on. I told him that another mechanic had done a diagnostic check back in October and had told me I had a bad catalytic converter. This mechanic suggested that a clogged catalytic converter might be the reason for the stalling, so I went ahead and had him replace it. Unfortunately, the check engine light still comes on and the car still dies (not to mention it sounds a little louder than I like with the new catalytic converter). Since we have ruled out the c.c. as a possibility, do you have any other suggestions as to where the problem may lie? Thanks.